The rGO/ZnCo2O4 nanocomposite (NCs) was synthesized using a hydrothermal method. The crystallite size, morphology, and optical properties of rGO, ZnCo2O4, and the rGO/ZnCo2O4 nanocomposite were extensively characterized using TG/DTA, FT-IR, UV-DRS, XRD, SEM with EDAX, and TEM techniques. The synthesized rGO/ZnCo2O4 NCs were crystalline with a cubic spinel structure and an average crystallite size of 19 nm, as confirmed by XRD. The optical bandgaps of pure ZnCo2O4 and the rGO/ZnCo2O4 nanocomposite were estimated to be 2.3 eV and 1.8 eV, respectively. The crystal violet (CV) dye was efficiently removed from an aqueous solution by photocatalytic degradation under visible light and sunlight irradiation in the presence of pure ZnCo2O4 and the rGO/ZnCo2O4 nanocomposite. The degradation results revealed that nearly 99.9 % of dye degradation was achieved with the rGO/ZnCo2O4 nanocomposite compared to pure ZnCo2O4 nanoparticles in 60 minutes. Hence, the rGO/ZnCo2O4 nanocomposite can be considered a promising and efficient photocatalyst for the degradation of crystal violet dye. The key highlight of this work is the low-cost, disruptive engineering strategy for synthesizing nanocatalysts for multifaceted applications.